1. Field of the Invention
This invention relates to novel neocarzinostatin derivatives, more particularly to neocarzinostatin derivatives represented by the formula (I); ##STR2## wherein N represents a neocarzinostatin residue, and R.sub.1 +R.sub.2 represents a residue of a polystyrene-maleic acid copolymer having a molecular weight of 2,500 to 80,000, and a process for producing the same.
2. Description of the Prior Art
Neocarzinostatin is a proteinic anticarcinogen produced in a media in which Streptomyces carzinostaticus var. F-41 is cultured (Japanese Patent Publication No. 42(1967)-21752 and U.S. Pat. No. 3,334,022). With respect to the primary structure of this substance, the total number of amino acid residues and estimated molecular weight have been reported to be 109 and 10,700, respectively, by Hiroshi Maeda who is one of the present inventors (Science, 178, 875-876(1972) and Arch. Biochem. Biophys., 163,379-385).